Hard body for wearing-surfaces and the like.



III IIIIIIIIIIIIIIIIIIIIIII 9.

1,088,858. Patented Mar. 3, 1914.

ses: Inventor Ezechiei W 'ntraub" @W Hisfft orne g;

UNITED STATES PATENT OFFICE.

EZECHIEL WEINTRAUB, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY. A CORPORATION OF NET/V YORK.

HARD BODY FOR WEARING-SURFACES AND THE- LIKE.

Application med October 27, 1909.

Specification of Letters Patent.

Patented Mar. 3,1914.

Serial No. 524,940.

To aZ-U whom it may concern Be it known that: I, Ezuennti. \VEIN- Times, a citizen of theIInited States, residing at Lynn, county of Essex, State of B'Iassaehusetts, have invented certain new and useful Improvements in Hard Bodies for \Vearing-Surfaces and the like, of which the followingis a specification.

It is the object of my present invention to produce a material suitable for use as meter jewels where sapphires are now-used,

and suitable tor use as dies in place of diemonds, and so hard and so free from crystalline structurethat it. can be used as a cutting material 01 a meted-working tool, or for other purposes rcquiringa very hard, dense body, capable of resisting the action of constant friction.

I have discoveredthat boron, either ure or nearly of conchoidal fracture with absence of any micro-crystalline appear; This material is harder tlpn sapp lire, and iswell adaptcdior use as the jewel of an electrical recording meter, and-for dies, drills and metal-working toolsof various kinds. The fused boron is devoid of crystalline structure, and in this respect is unique among very hard materials artificially produced,

which couldibe considered in this connection.

The accompanying drawing is a section or a. meter ewel somewhat enlarged.

According to one method of procedure, I

reduce boric anhydrid in excess with mag-.

nesium. The resulting. product contains boron associated with magnesium, or oxygen, or both, according to the proportions of the reacting materialsand the tempera ture of the reaction. It is pressed into stick form, and heated in a vacuum furnace to a tP'T'Ht'RiLUIC. of 1.200 degrees, or over, to m the stick slightly conductive. stick is then run as an electrode for a high potential are tipt-Ei'fltillg in hydrogen of sut' ticicn't do; i, to cause concentration of the are on the endof the stick. A pressure of hydrogen to about five inches of mercu is ordinarily; able, The treatment \\i h a high potcntiiikarc is fully disclosed inmy co-pending application Serial No. 524,947 of even date. This heat treatment drives from the stick its various impurities,

and if it is sutliciently prolonged can be used to. fuse the substance into a dense urc can be fused into largepi ms The black. glass-like head. By suitably regulating lite current through the furnace, the head an be held for a long time in a semisures or: blow holes. The beads are then ready f r the construetlon of meter jewels stood in the art of jewel grinding and polishing.

For some purposes an admixture of carbon, silicon, magnesium or ahuninuni is dee'isetble. This result can be obtained bv mixmg powdered graphite. silicon, or other desired element, with the impure boron before pressing the same into sticks for fusion in the arc furnace. By another method of making reduced with hydrogen by passinga mixture -of these materials into a high voltage alternating current are maintained between water-cooled copper electrodes, as described fullyfin my co-pending applicatioh Serial are sets up chemi's-al action between the hyvided boron in a pure condition, which is driven-outof' the active Zone by the action of the arc' blast. Some of'the reduced boron fuses on the electrodes and grows into beads and: rods. In this form the boron may be worked up at once into jewels or dies. Some .walls of the arc chamber inafinelyfdivided condition. The powder is pressed into sticks, which are fused by being made the electrode of the high potential are. operating in hydrogen, or by fusing in a vacuum furnace of the Arsem type, which is provided with a tungsten resistance heater in case pure boron is desired. It a. smali amount of can son. is not objectionable in the boron a graphite heater can be used in the furnace. If the presence 01". carbon, silicon, or other element, in the bead is desired, it can be added to the powdered boron before pressing into sticks. As another means for melting pure boron, or a mixture of boron and carbon, I may use an a re furnace of the type in which the charge is pressed into a stick preheated. to about 1200" as in an'f'fdrscm furnace and then operated as anode 101'" a low voltage mercury are running, in hydrogen, as disclosed in my application erial No. 346,253, filed December 4, 1906.

or diesv according to the method well under-' No. 524,939 of even date. The heatof the of the reduced boron is thrown outon-the' molten condition, and thus freed fromffis the. hard bodies of boron, or boron associated with carbon, the chlorid of boron is' drogen and the chlorid, liberating finely. di-- When fusing the charge by any of the procedures above (1 lribed,-the charge should be held molten r; semimolten for a time, sufiicient to freea from microscopic fissures and irregularitiesg" The hardness. toughness and density of the boronfafteri fir'sion,,and the entire absence of crystalline structure render the ma of boron, or of boron associated with carbon, I may proceed by building up rods'or sticks by gradual deposition of the desired components on a thin filament of carbon or other suitable conductive material. Thus if a base filament be heated in boron chlorid and hydrogen, pure boron is deposited on the filament to such a-depth that the conductor finally becomes a rod or stick consisting entirely of boron except for the relatively small carbon core on which the boron was initially deposited. Such a rod can be rendered dense and strong by sintering with current passed through the rod or in a tungsten vacuumfurnace, and can be broken up into small lumps f qrcuppi-ng and olishing to form meter ewels and the li e. If it is desired that the stick or rod of boron shall contain more carbon than that left by the original base filament, the deposition may be carried out in a gaseous mixture containing gasolene, carbon tetrachlorid, or the like, capable of breaking up to deposit carbon simultaneously with the deposition of the boron. This procedure is disclosed in my application, Serial No. 524,950, filed Oct. 27, 1910. These sticks canbe sintered and otherwise finished much the same as the sticks of pure boron.

What I claim as new and desire to secure by Letters Patent of the United States, is-

l. A meter jewel composed of a:hard, dense fusion consisting mainly of boron.

2. A. meter jewel formedof a fused body of boron and carbon. up

3. A pivot-bearing composed of a hard, dense fusion, consisting mainltlc Of boron.

4. A pivot-bearing formed of a fused body of boron and carbo a In witness whereof, I have hereunto set VVtnesses: JOHN A; MCMANUS, J r., CHARLES A. BARNARD. 

